96 Z71 Transmission HELP?!?!?!?!?!

Diesel_Fan · 12-07-2007, 07:09 PM

ok here we go. i bought a 96 Chevy Z71 350 Vortec w/ 4L60E auto w/ floor mounted 4wd shifter. this truck belonged to a friend of mine. a while back the trans that was in the truck quit on him, he replaced with a junkyard trans and it did not work, turns out some wires were burned or shorted and he had them fixed and it started working, which kinda says the other trans was still good. well i bought it and the trans was taking off in 3rd gear after warming up and i talked to a guy that owns a wrecking yard and he told me that it the year model was not the same i would have trouble with the transmission shifting properly, so i though heck i got the other trans so i'll put it in, well i did, and got it properly filled and changed the filter and all just to be safe, there was no metal on the magnet in the pan or anything and the fluid didnt smell bad or anything, but it will shift through 1st and 2nd but no 3rd gear, i also have the Service engine light staying on and going off and blinking at times and trying to maintain speed it backfires somewhat but the engine runs really good so im stumped at that. could this be electronic; ie: solenoid or something, sensors? ALSO i cannot get any scanner whether it be auto zones cheapos or High dollar mechanic shop scanners to read the code, the truck will not respond to the scanners, so i need some serious help please if anyone has any suggestions or advice i appreciate it very much.

mudseeker · 12-07-2007, 09:03 PM

does the scanner not link up to the truck at all, or does it just not pull any codes. if you can get the scanner to link up then have the mechanic run it in datastream mode and take the truck for a drive, should be able to find the problem that way.

if the scanner does not link up with the truck then you have a wiring problem with your DLC, either ground or power not being recieved.

mudseeker · 12-07-2007, 09:04 PM

Quote:

Originally Posted by 01Cummins

ok here we go. i bought a 96 Chevy Z71 350 Vortec w/ 4L60E auto w/ floor mounted 4wd shifter. this truck belonged to a friend of mine. a while back the trans that was in the truck quit on him, he replaced with a junkyard trans and it did not work, turns out some wires were burned or shorted and he had them fixed and it started working, which kinda says the other trans was still good. well i bought it and the trans was taking off in 3rd gear after warming up and i talked to a guy that owns a wrecking yard and he told me that it the year model was not the same i would have trouble with the transmission shifting properly, so i though heck i got the other trans so i'll put it in, well i did, and got it properly filled and changed the filter and all just to be safe, there was no metal on the magnet in the pan or anything and the fluid didnt smell bad or anything, but it will shift through 1st and 2nd but no 3rd gear, i also have the Service engine light staying on and going off and blinking at times and trying to maintain speed it backfires somewhat but the engine runs really good so im stumped at that. could this be electronic; ie: solenoid or something, sensors? ALSO i cannot get any scanner whether it be auto zones cheapos or High dollar mechanic shop scanners to read the code, the truck will not respond to the scanners, so i need some serious help please if anyone has any suggestions or advice i appreciate it very much.

so the old tranny had third and the new one doesn't?

Diesel_Fan · 12-07-2007, 09:56 PM

the tranny thats back in it is the original but the one they had put in it before i got it had all gears when cold until warm and then took off in 3rd gear, kinda like driving a hydrostatic in a tractor. but now i have 1st 2nd and no 3rd but dont know what problem could be whether electronic or mechanical???

mudseeker · 12-08-2007, 03:03 PM

i'm leaning towards electrical seeing as that was the problem before. i would drop the tranny agian and go through the wiring harness. the harness is a big tangled mess so dropping the tranny helps. pay close attention to the 20 pin connector on the passenger side, check for bent/broken pins or corrosion.

Diesel_Fan · 12-10-2007, 05:13 PM

just barely holding the gas maintaining speed through town its not exactly cutting out but backfiring and popping through the pipes, idk if this is part of the problem or not, i really need a nice dry day to mess with the plug on the park/neutral swith on the side of the tranny and i also was wondering if anybody could explain the shift solenoids to me because i know i had 3rd and overdrive in the other tranny so maybe i could use the ones out of it??? an illustrated breakdown would be great.

Hayden · 12-11-2007, 02:00 PM

I don't see how a bad tranny would make your engine pop and backfire. everytime I hear someone saying there engine does that I sound like a broken record but check fuel pressure. nothing to do with tranny problem though

shoman44 · 12-16-2007, 07:43 PM

when your engine light starts flashing at you, that is when you know u have something going wrong, if the light stays on steady more than likely is something simple to change o2 sensor or 1 of the millions sensors we have now on vehicle's .Plus u have to find out what codes are stored since u have a service light on there is a code,**** it sounds like u have a TPS going bad now i think about it.......

shoman44 · 12-16-2007, 07:44 PM

i have a 01 bonneville thought my trans was going bad that is how much my tps screwed it up. I would start there and see what happens.

Diesel_Fan · 12-17-2007, 03:37 PM

well the trans is definitely bad i have come to realize, i only have 1st and 2nd and maintaining speed through town around 2700-3200 rpms it starts poppin and backfiring at the exhaust and some people have said fuel pressure could be an issue i think i disagree because if i give it the gas it will drop down back into first and take off without a miss or a sputter and run like a top just holding it around 2600-3200 it does that so maybe it could be tps, if you could elaborate on this and the location of the tps i would appreciate it.

12-07-2007, 07:09 PM	#1
Diesel_Fan Senior Member Join Date: Jun 2007 Location: West Texas Posts: 101	96 Z71 Transmission HELP?!?!?!?!?! ok here we go. i bought a 96 Chevy Z71 350 Vortec w/ 4L60E auto w/ floor mounted 4wd shifter. this truck belonged to a friend of mine. a while back the trans that was in the truck quit on him, he replaced with a junkyard trans and it did not work, turns out some wires were burned or shorted and he had them fixed and it started working, which kinda says the other trans was still good. well i bought it and the trans was taking off in 3rd gear after warming up and i talked to a guy that owns a wrecking yard and he told me that it the year model was not the same i would have trouble with the transmission shifting properly, so i though heck i got the other trans so i'll put it in, well i did, and got it properly filled and changed the filter and all just to be safe, there was no metal on the magnet in the pan or anything and the fluid didnt smell bad or anything, but it will shift through 1st and 2nd but no 3rd gear, i also have the Service engine light staying on and going off and blinking at times and trying to maintain speed it backfires somewhat but the engine runs really good so im stumped at that. could this be electronic; ie: solenoid or something, sensors? ALSO i cannot get any scanner whether it be auto zones cheapos or High dollar mechanic shop scanners to read the code, the truck will not respond to the scanners, so i need some serious help please if anyone has any suggestions or advice i appreciate it very much.

12-11-2007, 02:00 PM	#7
Hayden Senior Member Join Date: May 2006 Location: Bay City,Michigan Posts: 387	I don't see how a bad tranny would make your engine pop and backfire. everytime I hear someone saying there engine does that I sound like a broken record but check fuel pressure. nothing to do with tranny problem though __________________ There Is No Replacement For Displacement

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12-07-2007, 09:03 PM	#2
mudseeker Senior Moderator Join Date: Feb 2006 Location: michigan Posts: 7,155	does the scanner not link up to the truck at all, or does it just not pull any codes. if you can get the scanner to link up then have the mechanic run it in datastream mode and take the truck for a drive, should be able to find the problem that way. if the scanner does not link up with the truck then you have a wiring problem with your DLC, either ground or power not being recieved.

12-07-2007, 09:56 PM	#4
Diesel_Fan Senior Member Join Date: Jun 2007 Location: West Texas Posts: 101	the tranny thats back in it is the original but the one they had put in it before i got it had all gears when cold until warm and then took off in 3rd gear, kinda like driving a hydrostatic in a tractor. but now i have 1st 2nd and no 3rd but dont know what problem could be whether electronic or mechanical???

12-08-2007, 03:03 PM	#5
mudseeker Senior Moderator Join Date: Feb 2006 Location: michigan Posts: 7,155	i'm leaning towards electrical seeing as that was the problem before. i would drop the tranny agian and go through the wiring harness. the harness is a big tangled mess so dropping the tranny helps. pay close attention to the 20 pin connector on the passenger side, check for bent/broken pins or corrosion.

12-10-2007, 05:13 PM	#6
Diesel_Fan Senior Member Join Date: Jun 2007 Location: West Texas Posts: 101	just barely holding the gas maintaining speed through town its not exactly cutting out but backfiring and popping through the pipes, idk if this is part of the problem or not, i really need a nice dry day to mess with the plug on the park/neutral swith on the side of the tranny and i also was wondering if anybody could explain the shift solenoids to me because i know i had 3rd and overdrive in the other tranny so maybe i could use the ones out of it??? an illustrated breakdown would be great.

12-16-2007, 07:43 PM	#8
shoman44 Junior Member Join Date: Dec 2007 Posts: 17	when your engine light starts flashing at you, that is when you know u have something going wrong, if the light stays on steady more than likely is something simple to change o2 sensor or 1 of the millions sensors we have now on vehicle's .Plus u have to find out what codes are stored since u have a service light on there is a code,**** it sounds like u have a TPS going bad now i think about it.......

12-16-2007, 07:44 PM	#9
shoman44 Junior Member Join Date: Dec 2007 Posts: 17	i have a 01 bonneville thought my trans was going bad that is how much my tps screwed it up. I would start there and see what happens.

12-17-2007, 03:37 PM	#10
Diesel_Fan Senior Member Join Date: Jun 2007 Location: West Texas Posts: 101	well the trans is definitely bad i have come to realize, i only have 1st and 2nd and maintaining speed through town around 2700-3200 rpms it starts poppin and backfiring at the exhaust and some people have said fuel pressure could be an issue i think i disagree because if i give it the gas it will drop down back into first and take off without a miss or a sputter and run like a top just holding it around 2600-3200 it does that so maybe it could be tps, if you could elaborate on this and the location of the tps i would appreciate it.